How The Attack In Benghazi Led Us To Hillary Clinton's EmailsAhead of Tuesday's first Democratic presidential debate, we revisit the facts of the Benghazi investigation and how it became potentially damaging to the political fortunes of Hillary Clinton.

Ahead of Tuesday's first Democratic presidential debate, we revisit the facts of the Benghazi investigation and how it became potentially damaging to the political fortunes of Hillary Clinton.

RENEE MONTAGNE, HOST:

Democratic candidates will step behind their podiums tonight in Las Vegas for the first Democratic debate. And one subject sure to come up is the long-running congressional investigation into the attack in Benghazi, Libya. That Republican-led committee has recently expanded its line of questioning to include the private email server Hillary Clinton used as secretary of state. For a refresher on these two complicated controversies, we're joined by NPR justice correspondent Carrie Johnson. Good morning.

CARRIE JOHNSON, BYLINE: Good morning, Renee.

MONTAGNE: And remind us about this committee, the House Select Committee on Benghazi, which was essentially set up to do one thing in what amount of time?

JOHNSON: So it all goes back to that attack three years ago in 2012 in Libya at the diplomatic compound in Benghazi on September 11. And, of course, Renee, four Americans, including Ambassador Chris Stevens, died in that attack. Those deaths raised a lot of questions, like whether security was sufficient before the attacks and whether the Pentagon might have sent reinforcements to help the diplomats and contractors who were under siege. Since Hillary Clinton was secretary of state when the attack happened, her actions were under the microscope, too, there.

MONTAGNE: So - I mean - but - it's a very specific sort of investigation. And the Senate Intelligence Committee looked at some of these questions already, and what did it conclude?

JOHNSON: Well, Benghazi clearly was very dangerous. There were militias running around. It was a very unstable place. And security was not appropriate given that danger at the diplomatic compound. But they and others have concluded that no military forces were in position to come to the aid of the diplomats in time to help them during that siege in 2012, and State Department officials who worked there at the time say that, too.

MONTAGNE: Well, this has continued to be a political issue for Hillary Clinton because the U.S. House of Representatives has kept digging. I mean, what are they spending their time on?

JOHNSON: Well, the leader of this investigation in the House of the House Special Committee on Benghazi is Trey Gowdy, a Republican from South Carolina. And he says he's uncovered some evidence. He won't say what yet. They cast doubt on the idea that no military forces were in position to help in 2012. Over the past several months, though, Renee, as you mentioned, Democrats say that the Benghazi Committee has started looking at Hillary Clinton's private email setup, this server she operated out of her home at the same time she was a government official.

And they're investigating whether classified information was flowing between she and her aides in a way that was unprotected. Gowdy's spokesman - Trey Gowdy's spokesman has released some emails suggesting that Clinton was getting messages from her aides about security and intelligence in Libya - messages that may have contained secrets.

MONTAGNE: So what are the leaders of the Benghazi Committee saying about that?

JOHNSON: Well, the leaders of the committee are saying that they have a lot more work to do. But the Democrats, as you mention, are really try - starting to cry foul here. They say this investigation has gone on too long. It's become too politicized. And it's merely a tool to attack Clinton during the campaign. You're not going to believe this, but the story took another turn over the last few days.

A whistleblower on the committee, who works for the committee, says that he was treated unfairly by Republicans. He wants to sue. And he says he wanted to keep digging on the Benghazi attacks themselves, but instead, his bosses became single-minded about the email scandal. He says he left to do some military service. When he came back to work on the House Committee, his supervisors mistreated him.

MONTAGNE: And, again, this is all going to come up in the debate tonight, probably, as to, you know, Hillary Clinton's situation as a candidate. But finally, the FBI is also on the case.

JOHNSON: Yes, the FBI investigation is a little bit blurry. It appears to involve handling of classified information and security of that information. Hillary Clinton herself is not a target of the probe. President Obama, over the weekend, said it may have been a mistake to operate a private email server, but he didn't believe that she had endangered national security in any way. And we're going to this fight continue in the House because Trey Gowdy and Republicans there say they don't believe the whistleblower, and they have a lot left to investigate.

NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.